He cheated. How do I get past it?

A week ago I found out that he cheated on me. I tried to leave but he was balling asking me to come back. This is a man who holds his feelings in, never cries. I went back, he said he would change and he was done with the games. But I freak out often and now I have no idea how I can trust him again. On top of all that I think I'm pregnant. I don't know what to do.